The following flexible substrate strip LED light engines of Applicant's assignee are known, and are each incorporated hereby in their entirety as if fully set forth herein: Pat. Pub. US 2015/0129909 (Speer et al.) and US 2015/0092413 (Li et al.).
Known is also Pat. Pub. US 2012/0241806 (Kim), showing at the embodiment described at FIG. 9 therein a base layer formed of FR4, a bonded copper foil layer, and the outer insulating layer. The Kim '806 circuit is understood to be formed by conventional lithographic process. Such a process uses a copper foil held by glue to an FR4 material to form the copper clad substrate (i.e., the insulating film layer is not required to hold the copper foil layer in place), which is then etched in a bath to remove copper from where traces are not needed, thus requiring an expensive mask to be made, to require batch processing, and to require the use of inconvenient etch materials.
The following are also known in U.S. Pat. No. 8,314,566 (Steele); U.S. Pat. No. 5,178,685 (Borenstein); U.S. Pat. No. 5,151,386 (Bottari); Pat. Pubs. 2008/0295327 (Aeling); US 2015/0092429 (Speer); 2015/0129899 (Speer); 2008/0191220 (Daniels).